Yes, I did think about the 241 first but it doesn't have the Jeep compatible speedo sender - JB designed the 241 shorty for GM vehicles and nobody has confirmed that the bolt holes are exactly aligned between 241 & 242. I figured, the Wrangler kit would be easier to interface to an XJ and that their 231 kit would remain a viable product for some years to come.
The 4 to 5 bolt adapter itself will have production costs, but as it's fairly simple to produce it is likely to be cheaper than a lost wax casting for a new tail cone. I would go the casting route but I don't know enough about the speedo sender that JB uses. If I could do the sender myself, I would have the tail cone cast and avoid the JB parts altogether.
The extra length that the 4-5 bolt adapter adds isn't an issue on an XJ, it will still be shorter than an RE H&T.
The 4 to 5 bolt adapter itself will have production costs, but as it's fairly simple to produce it is likely to be cheaper than a lost wax casting for a new tail cone. I would go the casting route but I don't know enough about the speedo sender that JB uses. If I could do the sender myself, I would have the tail cone cast and avoid the JB parts altogether.
The extra length that the 4-5 bolt adapter adds isn't an issue on an XJ, it will still be shorter than an RE H&T.